what she said remember is a v. v. v. age appropriate reaction.
at 5 they are very logical. her saying she is pretty is the same as saying i am a girl. its the statement. its the truth.
as a mother i wouldnt focus on this at all. 'yes you are pretty' and leave it at that. dont freak out or go into the ethics of that statement. in time she will realise the advantage and the disadvantages of being pretty and THATS when you come in big time. worry about it when she gets to 4th or 5th grade when girls get catty.
people made a lot of comments to dd. i ignored them. when dd asked me i replied truthfully in short sentences. yes you are ____. we didnt explore further adn we went on our merry ways. there is so much other things to focus on. and looking back i realise what is important as a parent is to figure out where you stand. because as your child grows older - more than ads or barbie dolls its her friend, her classmates who will define her body image.
what makes a HUGE difference is where you put your focus on. dd was being teased as being fat. she asked me if i thought she was fat and i said by today's society standard you are fat. however it doesnt bother me and i dont really care about it because this is baby fat that you will slowly start to lose when you grow older. and if you dont we'll see what's going on. right now you are doing much better with food than X a skinny boy in her class who eats a lot of unhealthy food. end of conversation. end of subject.
i never put being pretty and being kind in the same conversation as if one is better than the other. am i pretty mom - 'yes i think you are pretty and many find you pretty too'. end of conversation. at 5 being kind or such qualities are a whole different conversation. always with an observation. when you picked up that babies toy she had thrown on the ground the mom didnt see was a kind thing to do and i want to tell you i really appreciate your action. dd was like <shrugg> whatever. it wasnt a big deal to her at all.
i would not worry about self worth at this age at all (HAH!!! me saying that in retrospect. i felt that way when dd was that age too). but looking back i feel i spent a lot of wasted time and making sure on big lofty ideals like self worth, etc. kids didnt need that.
what matters is how YOU as a parent live your life and what you express through your actions what is important to you. THAT is what kids pick up on - not what commercials or strangers say. if YOU make 'it' a big deal, then 'it' becomes a big deal, no matter what society or commercials say about 'it'. like if you point out oh looking good is not important but you spend an hour every morning prettying yourself up - guess what your kid is going to believe?!!!!
so dont worry about self worth for dd. you walk tall and define your own self worth and that is what your dd is going to see.